Weird rash on my son

Two days ago my son had some weird rash on his arm that appeared as though he had been burned. And then yesterday that same rash appeared in another part of the arm. I cannot determine what it is and have never seen anything like it. It feels rough as well. Somehow our phone line is out so I cannot call the doctor. I thought maybe someone on here would know.

Yes, he jerked his arm back when I touched it to examine it more closely. Thankfully, the phones lines have been fixed and we have an appointment this afternoon. I know it seems like I worry too much with him but I cannot help it. I love him so much and do not want anything happening to him.

I know our two small dogs were nudging him, gently, and his 10 yr old cousin gave him a stuffed beanie baby toy from his room. There are a number of things. We use fragrance free and dye free detergent for sensitive skin and that doesn't bother him. Also, his soap is Dove Sensitive, and he's been using that since birth. I am hoping it is not the dogs but, if it is, my son comes first. He has been spitting up, which concerns me even more and actually sleeping (but I think that is because he is getting older). I am going to be one of those "worry wart" mommies. lol